The present invention relates to a pentathienyl-fluorene copolymer. To function optimally, transistors need to be turned on and off within a narrow voltage range. The voltage required to actuate a transistor is referred to as the threshold voltage, the stability of which depends on the properties of the semiconducting material in the transistor. Many semiconducting materials that would otherwise operate in transistor applications, are inappropriate due to a high variability of the threshold voltage that results from the use of these materials. Consequently, the search for semiconductors with low threshold voltage variability is an ongoing challenge in the field of semiconductors for transistor applications.